Traditional telescoping bleachers comprise long rows of wooden planks affixed to upstanding leg elements attached to various types of supporting structures. Not only is such seating notoriously uncomfortable, but also it is susceptible to wear, splintering, water soaking, rot, oxidation of fastening elements, and vandalism. The substitution of formed sheet metal of a weather resistant type such as aluminum or galvanized steel for the wooden planks has alleviated some of these problems but at far greater expense and with the introduction of new problems. Thus, metal planking remains uncomfortable, and while it is not as subject to wear, splintering and rot as wood, it is subject to denting, cracking, and expansion and contraction with temperature and vandalism.
Numerous attempts to solve some or all of these problems have been made with varying degrees of success. For example, it has been suggested to cover the wooden planks with cushioning material and to then cover the cushioning material with a heavy, tough plastic cover. Covering the planks with molded plastic elements without cushioning therebetween has also been suggested (U.S. Pat. No. 3,397,011). These suggestions helped preserve the wood, but they did not provide solutions to the other problems. Molding plastic covered seats as individual modular units, with each unit designed to accommodate a single person, and attaching them side by side to each other or to a base to form a continuous row of seats has also been suggested. (U.S. Pat. Nos. 3,012,818, 3,466,087). Such constructions satisfy the need for regular demarcation of assigned seats, but they are expensive and difficult to install. Other prior suggestions include providing stamped metal or molded plastic portable modular seat units adapted to being placed over conventional seating and having a compound curved shape for improved comfort. (U.S. Pat. Nos. 2,970,638, 3,466,087). In addition various ways to connect such individual seating modules to each other and/or to a base to form continuous rows thereof have been suggested including the use of (a) attaching flanges bolted or soldered together (U.S. Pat. No. 1,978,494); (b) tie bolts (U.S. Pat. No. 3,012,818); (c) separate connecting members which fit over and clamp the adjacent ends of the modules (U.S. Pat. No. 3,466,087); (d) screws or bolts (including "tamper proof" heads) through the front walls or underneath surfaces of the modules (U.S. Pat. Nos. 3,298,045, 3,397,011, 3,531,157), or through the clamping members (U.S. Pat. No. 3,466,087).
While some of these suggestions have provided the desired comfort, and others have adequately protected the underlying base, they have all been relatively expensive to construct and install, and none has provided completely hidden fasteners as distinguished from exposed "tamper proof" bolt or screw heads.
More recently it has been suggested that hollow, molded polymeric structural foam seating modules be assembled together to form the entire bench portion of the seating assembly rather than as a protection or substitute for the traditional wooden planking. Such constructions have successfully dealt with some of the problems facing the seating industry. For example, structural foam is very durable, it is relatively inert, it resists ultra-violet, denting, cutting and burning; it is light-weight; it can easily be tinted or colored throughout rather than merely on the surface; it can be given a textured surface for improved appearance as well as to improve resistance to slippage or dirt; it can be easily manufactured into substantially any desired shape or configuration at comparatively low cost.
In spite of these advantages of the material, the constructions employed have not been highly successful. The modules, for instance, have been molded as single, integral units presumably for reasons of strength, durability, and the avoidance of unauthorized disassembly by vandals. This mode of construction, however, entails high manufacturing costs, results in bulky articles which are expensive to store and ship because they cannot be nested and it also makes on site assembly and/or replacement difficult if hidden, tamper-proof fastenings are used. Similarly, in an effort to maximize foot room for the seat occupant and for the row behind while at the same time providing a comfortable molded seat, presently available seating of this type is of a generally triangular cross section. As a consequence, the base portion of such modular seating where the module is affixed to the support structure is comparatively narrow at the very point where the tipping forces encountered in use will induce the greatest structural stress. While molded structural foam has many attractive physical properties, the fact remains that it is still plastic and relatively weak compared to steel. Therefore, any construction employing it which concentrates bending stress at a narrow point will be prone to failure. As a result, the previously known seating modules employing structural foam required the addition of a metal reinforced base which was expensive in the manufacture and/or installation of the seating. In addition, the unitary modular construction of such seating prevented the modules from telescoping one into the other for space saving during shipment and storage. Additionally, in the context of nesting or telescoping bleachers the front edges of the seats of the currently available plastic seat modules project forwardly so that when the bleachers are stowed the front edges provide a ladder-like foothold for persons wishing to climb the structure. This is undesirable especially when such bleachers are installed in school gymnasiums and the like. The potential for damage to the bleachers and for liability for personal injury resulting from falls which may occur from such misuse of these structures are distinct disadvantages.
Replacement of damaged modules is also a problem. Currently available systems require the replacement of an entire module when any part of it is damaged. Also, the disassembly or removal of more than one module may be required, when only one module may be damaged and thereby unnecessary extra cost is incurred.
Accordingly, it is an object of this invention to provide a novel, hollow, molded structural foam seating module which solves the problems discussed.